1. Field of the Invention
The present invention relates to a molecular electronic device, and more particularly, to a molecular electronic device in which a functional molecular active layer capable of providing electrical characteristics is interposed between two metal electrodes.
2. Description of the Related Art
In recent years, as it has become known that organic materials have semiconductor characteristics due to the presence of conjugated pi electrons, much research into organic semiconductor devices has been conducted. Most of the research is related to electron transport characteristics of an organic material layer interposed between two metal electrodes. Recently, the development of molecular switching devices or memory devices using functional molecules having aromatic rings with electron-acceptor groups has been actively conducted. In particular, as commercially available semiconductor devices which are nano-sized (of the scale of several tens of nanometers) are being competitively developed, the development of more highly integrated and further miniaturized molecular electronic devices is increasingly in demand.
A currently available molecular electronic device is fundamentally structured such that a functional molecular active layer is interposed between two metal electrodes. The functional molecular active layer provides organic semiconductor characteristics between the two metal electrodes. Recently, a technique of forming a functional molecular active layer as a molecular monolayer on a metal electrode using a self-assembly process has been proposed. According to this technique, the functional molecular active layer formed as a molecular monolayer has a very thin thickness of several nanometers, and thus, when a metal for forming an electrode is deposited on the functional molecular active layer, damage to the functional molecular active layer may occur. In particular, when using Ti and Au as metal materials, Ti and Au may permeate a relatively sparse functional molecular active layer upon deposition, thereby causing a short circuit in molecular electronic devices. This makes practical utilization of molecular electronic devices difficult.